parfocal incompatible with autofocus?

[Todd Terry]

[Gary Huff] “if I could afford it, and use that 90% of the time.”

Yup… and thus the problem with cine zooms.

Even though I rarely if ever change a focal length during a shot, sometimes it does get tiresome changing primes and I wouldn’t mind having a zoom mounted instead. The only zoom I ever use is my vintage Russian Foton 37-140mm, which is beautiful glass and gives pretty much exactly that vintage Cooke Speed Panchro look that most DPs still go crazy for… but it is slooow as molasses.

In a perfect world there’d be a very wide range cine zoom that is also very fast and lightweight… and affordable. Say, something in the old Angénieux range of 12-120, that was f/2.0 or faster, wasn’t a foot long and six pounds, didn’t flare, and didn’t cost as much as my first house. Unfortunately you are more likely to find a leprechaun.

Canon does make two great (and fast) cine zooms that I’d love to have… but for range I’d need both of them and last time I looked they were pushing 50 grand each (and are still quite large and heavy). I haven’t even come close to being able to justify that as a purchase, and no rental houses in our area stock them.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Bob Cole]

Great work! and very interesting examples of AF. And very impressive, that relatively inexpensive Canon “still” lenses with AF can be so useful with video.

I have to find a C300M2 somewhere to try it out, but meanwhile:

With Face Detect, can you select a particular face and have the camera track it, changing focus as that one face moves closer to the camera? If the person walks behind an object for a second, will Face Detect hold its fire and keep the focus at the setting where the face disappeared from view?

Bob C

[Gary Huff]

[Todd Terry] “In a perfect world there’d be a very wide range cine zoom that is also very fast and lightweight… and affordable. “

Unfortunately, that defies the laws of physics. Fast, lightweight, and with a useable range. Once you start making it heavier, that means more materials. Once you start making it more useable wide open, that’s more craft in the creation of the glass. More materials needed and precision in the glass means its more expensive.

I’ll take what Canon is doing with the f/4 Cine zooms as a fine trade-off with the modern sensors that have greatly increased sensitivity.

[Gary Huff]

[Bob Cole] “With Face Detect, can you select a particular face and have the camera track it, changing focus as that one face moves closer to the camera? If the person walks behind an object for a second, will Face Detect hold its fire and keep the focus at the setting where the face disappeared from view?”

You can pick the face you want to use. It will highlight all faces it detects and you use the joystick to swap around which face is targeted. Unfortunately, if it loses the face, the DPAF resorts to the adjustable targeting reticule, and it currently does not target where the face was last detected. So if you had targeted in the lower third of the frame, and the person whose face you are detecting turns their head to talk to someone behind them, it will immediately switch to the DPAF target and focus on whatever is there. I have asked Canon to fix this so that the DPAF target is adjusted to be where the last area of face detection was, but this has yet to be implemented.

You can tell the C300 Mark II to only use Face Detect, and so it does nothing when it loses the target, but then you’ll have to disable AF and go manual if you need to focus on anything else. And to switch it back to normal DPAF operation, you have to go through the menus, so it’s not ideal.

[Todd Terry]

[Gary Huff] “Unfortunately, that defies the laws of physics.”

Obviously… hence my leprechaun analogy. Or Unicorn.

The Canon f/4 is probably a decent trade-off… but a lot slower than I’d like.

The Canon 14-60mm is reasonably fast at f/2.6… but that’s not great range on the long end, and it’s $43,000.

For something in the f/4 range I’ll stick with my Russian Foton.

It’s definitely a challenging world sometimes, optically. And otherwise.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com